body{
    background-color: #cccccc;
}
a{
    /*由于a是行内块元素，所以没有行高，所以将他转换为行内块元素*/
    text-decoration: none;
    width: 300px;
    height: 300px;

    display: inline-block;
    text-align: center;
    line-height: 50px;
    color: skyblue;
    font-size: 22px;

}
a:hover{
    background-image: url('../image/05.jpg');
    background-repeat: no-repeat;

}